/**
 * Licensed to Apereo under one or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information regarding copyright ownership. Apereo
 * licenses this file to you under the Apache License, Version 2.0 (the "License"); you may not use
 * this file except in compliance with the License. You may obtain a copy of the License at the
 * following location:
 *
 * <p>http://www.apache.org/licenses/LICENSE-2.0
 *
 * <p>Unless required by applicable law or agreed to in writing, software distributed under the
 * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
 * express or implied. See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apereo.portal.concurrency.locking;

/**
 * DB based locking DAO.
 *
 * <p>Locks are NOT reentrant. If ServerA tries to call getLock twice the 2nd call will return
 * false.
 */
interface IClusterLockDao {

    /**
     * Get a cluster mutex with the specified name.
     *
     * @param mutexName the name of the mutex
     */
    ClusterMutex getClusterMutex(String mutexName);

    /**
     * Lock the specified mutex
     *
     * @param mutexName The mutex to lock
     * @return The ClusterMutex if the lock was successfully acquired, null if the lock is already
     *     held.
     */
    ClusterMutex getLock(String mutexName);

    /**
     * Update the specified mutex, the mutex must already be locked by this server. It is expected
     * that a locked mutex is updated at a regular interval to inform other servers that the lock is
     * still live.
     *
     * @param mutexName The mutex to update
     * @throws IllegalMonitorStateException if this server does not currently own the lock
     */
    void updateLock(String mutexName);

    /**
     * Release the specified mutex, the mutex must already be locked by this server.
     *
     * @param mutexName The mutex to release
     * @throws IllegalMonitorStateException if this server does not currently own the lock
     */
    void releaseLock(String mutexName);
}
